This invention relates to a filter and collection device for the filtration, collection and isolation of materials and use thereof. The invention is exemplified by use of the device to separate heavy metals from non-heavy metal generated during dental procedures.
During procedures that generate waste where separation of different waste is desirable, procedures that generate waste and solids of value where separation of the solids of value and the waste is desirable, or procedures that generate small solids of value where the separation and collection of the small solid particles by material type is desirable, there is a lack of a device capable of filtering or separating material collected during or after these various procedures.
An example of one type of such procedures, where such a device would be of use is dental procedures. During dental procedures, typically the dental practitioner and dental assistant sit on adjustable stools on opposite sides of the reclined contour dental chair near the patient""s head. The dentist prepares the patient""s teeth for restoration with a high speed turbine handpiece (drill) and other instruments to remove decay and shape the tooth to be restored. During some parts of the procedure a water spray is used to wash the tooth and the operating field (washed field technique). Tooth structure particles and/or existing old defective silver-mercury amalgam or gold restorations are aspirated from the operating field of the oral cavity. This aspiration is done by the dental assistant using a vacuum tip attached to a conventional flexible vacuum tubing. The solids, water spray and oral fluids are deposited via the vacuum tubing into a perforated plastic screen located in the vacuum conduit line leading to the sewer line. However, solids of small size that escape the perforated plastic screen are deposited into the sewer line. The materials collected during oral surgery often include blood, gingivel tissue, suture clippings, pieces of bone, pus and other infection fluids. The materials collected during prophylaxis often include calculus and cleaning materials.
The dental filter currently in use suffers from many disadvantages and fails completely to accomplish the function of a dental filter:
(a) The particles of the silver-mercury amalgam, gold and tooth structure produced by the drilling procedure are reduced to a very small particle size. These small particles escape through the perforations of the plastic screen and are lost into the sewer system.
(b) Mercury, also a heavy metal, is a liquid at room temperature and in its free state is a very toxic substance. Therefore, if liquid mercury is accidentally spilled on operating surfaces or on the floor, it can be aspirated up by the vacuum tip. However, it easily escapes through the plastic screen perforations. The mercury then enters the sewer lines and ultimately into the environment.
(c) Another defective feature in the above described filter screen is that the water and oral fluids are aspirated together with the solid materials being removed from the oral cavity.
(d) The perforated screen type filter does not allow for the separation of different wastes during the dental procedure.
Other systems, while not using continuously running water as a vacuum source, nevertheless uses a centrally-located debris canister or variant thereof where the extracted debris is collected during operation. The disadvantage of such systems is that such a debris canister must be often and regularly emptied and, consequently the centrally located system must be shut down during this time. Such systems can present a significant problem when the canister must be emptied while the dentist is performing a dental procedure on a patient. Some of these systems incorporate mechanisms which are able to detect the moment of need for emptying the debris canister and are further capable of disposing of the contents therein. Such systems cannot separate heavy metals, including mercury, and other solids from non-heavy metal liquids.
Common to each of these dental vacuum systems is a problem associated with obtaining optimal dental waste mass flow rates while minimizing both negative vacuum pressures necessary for such flow rates and facilities space needed for locating the vacuum canisters. The optimal dental waste mass flow rate is approximately 5 cubic feet per minute. Heretofore, such a mass flow rate is obtainable only when 40-55 gallon debris canisters and their associated high required negative vacuum pressures are used in conjunction therewith. Additionally, installation or removal of these dental vacuum systems require considerable plumbing or property improvements to access the required water, vacuum lines, and electricity. In such a case, the inconvenience and expense incurred by the dental practitioner can be considerable.
Another example of procedures that such a filter and collection device would be of use is jewelry manufacture and repair, and lapidary procedures. There is a lack of a device that can separate and collect the different precious material cast as carvings, trimmings, filings, shavings or the like. The common practice is to use a different holding tray for each precious material to be worked on. However, this system has the disadvantage of requiring further consolidation of the carvings, trimmings, filings, shavings or the like from each tray and the storage of the various trays is space consuming, tedious, and inefficient.
Another example of procedures that such a filter and collection device would be of use is in scientific research procedures that involve the use of biological hazardous waste, radioactive material, carcinogens, mutagens or other toxic or noxious materials that are spilled or to be disposed of as waste. There is lack of a device that can separate and collect the toxic or noxious materials. The common practice is to put these materials into a plastic bag by hand with gloves as protection, and to dispose of the plastic bags and gloves. When there is an accidental spill of liquid waste, then the liquid is first absorbed by absorbent material, such as paper towels. However, this system has the disadvantage of proximity of the hand to the material being disposed of, the generation of more tainted waste, including the absorbent material, gloves, and plastic bags.
It therefore is of interest to develop a device capable of separating solid material from liquid material, one solid material from another solid material, and one liquid material from another liquid material. This device would be capable of being easily adapted to current vacuum systems, inexpensive to manufacture, able to salvage materials of value, and able separately collected waste materials requiring special disposal, such as mercury, biological hazardous waste, radioactive waste, carcinogens, mutagens, and other toxic or noxious waste.
U.S. Pat. No. 4,326,952 (1982) to Blake discloses an apparatus for recovering precious metal particles from a liquid mixture environment which utilizes a plurality of baffled compartments successively arranged in a sealed chamber.
U.S. Pat. No. 4,385,891 (1983) to Ligotti discloses a dental apparatus for preventing loss of precious metal particles from a mixture drawn from the mouth of a dental patient using a perforated baffle.
U.S. Pat. No. 4,564,374 (1986) to Hofmann discloses a device for incorporation in dental suction apparatuses for separation of liquid and solid components.
U.S. Pat. No. 4,761,235 (1988) to Haentjens discloses a waste collection device for accumulating solid waste downstream of a kitchen garbage grinder, which includes a separator for settling solid material from waste water and a removable waste accumulating container into which household garbage is collected.
U.S. Pat. No. 4,957,621 (1990) to Rohloff discloses a water jet cutting system, which uses a baffle plate to remove abrasives from the liquid before the liquid is passed through it.
U.S. Pat. No. 5,114,578 (1992) to Sundstrom discloses a settling apparatus for the separation of amalgam from waste water in a dental procedure, which includes an inclined passage through which water is caused to flow from below and upwards while depositing amalgam.
U.S. Pat. No. 5,741,397 (1998) to Kraver discloses an apparatus for processing combined liquid and solid dental waste from a patient""s mouth such that the solid waste is separated from the liquid waste.
U.S. Pat. No. 5,797,742 (1998) to Fraker discloses an amalgam solids collecting apparatus of the type for collecting an accumulation of a generally separable mixture of solids and liquids, including amalgam solids, and separating the solids from the liquids.
U.S. Pat. No. 5,967,780 (1999) to Morrissey discloses a vacuum receptacle method for accumulating, holding and disposing of liquids and certain solids that are evacuated from the mouths of dental patients by a suction tube during dental procedures, wherein a baffle is provided to impact and decelerate dental debris as it enters the receptacle.
The invention is a device that can separate and collect materials by using an air flow created by a conventional vacuum system, a manifold, a collection chamber, an adjustable baffle plate, and the force of gravity. The invention allows for the separation of any material (collect mode) from another material (pass-through mode). The device is switched from the collect mode to the pass-through mode by simply adjusting the position of the adjustable baffle plate. In the collect mode, any material drawn in by vacuum strikes the baffle plate, and by the effect of gravity falls into the collection chamber. When the chamber is sufficiently filled, the chamber is unscrewed from the manifold and a lid is screwed onto the chamber. This seals the chamber for storage of the collected material. A new collection chamber is then screwed into its place in the manifold. In the pass-through mode (FIGS. 3, 3A), material not desired to be collected bypasses the face of the baffle plate and the collection chamber. The invention encompasses the use of the device to separate one material from another material. The invention also encompasses the method of separating and collecting one material from another material by aspirating one material so that it bypasses the collection chamber, adjusting the position of the baffle plate, aspirating another material so that it is deflected by the baffle plate into the collection chamber. This device finds use in the separation of one or more precious and/or toxic substance for jewelers, goldsmith, gemologists, and like professionals.